W2 CODES for Box 12:

A = uncollected social security on tips.

B = uncollected Medicare tax on tips.

C = taxable cost of group-term life insurance over $50,000.

D = 401(k) contributions.

E = 403(b) contributions.

F = 408(k)(6) contributions.

G = 457(b) contributions.

H = 501(c)(18)(D) deferrals.

J = nontaxable sick pay (information only, not included in boxes 1, 3, or 5)

K = 20% excise tax on excess golden parachute payments.

L = substantiated employee business expense reimbursements (nontaxable)

M = uncollected social security tax on taxable cost of group-term life insurance over $50,000.

N = uncollected Medicare tax on taxable cost of group-term life insurance over $50,000.

P = excludable moving expense reimbursements paid directly to employee (not included in boxes 1, 3, or 5).

Q = nontaxable combat pay.

R = employer contributions to your Archer MSA; report on Form 8853.

S = employee salary reduction contributions under 408(p) SIMPLE Plan (not included in box 1).

T = adoption benefits (not included in box 1); complete Form 8839.

V = income from exercise of stock options (included in boxes 1, 3, and 5).

W = employer contributions to your Health Savings Account; report on Form 8889.

Y = 409A contributions.

Z = 409A income on nonqualified deferred compensation plan (also included in box 1); subject to an additional 20% tax plus interest.

AA = Roth contributions to a 401(k) plan.

BB = Roth contributions to a 403(b) plan.